Letter to the Glyco-Forum: Effective glycoanalysis with Maackia amurensis lectins requires a clear understanding of their binding specificities

Abstract

Many researchers use MAL (Maackia amurensis leukoagglutinin) and MAH (M. amurensis hemagglutinin), the seed lectins from M. amurensis, as glycoanalytical tools to probe biological targets for α2-3-linked sialic acids. The carbohydrate-binding specificities of these lectins have been carefully defined in several independent studies (Table I). However, investigators using M. amurensis lectins (MALs) for glycoanalysis often cite these specificities incorrectly (Table II). One reason for this discrepancy is that the M. amurensis seed lectins have been given a variety of different, but highly similar, names (Table I). This makes it particularly difficult to extract the correct binding specificities of these two distinct lectins (termed MAL and MAH herein) from the literature. Another reason for this discrepancy is that the technical specifications provided by some commercial vendors' cite binding specificities that differ from those defined in direct scientific studies (Tables I and II). Thus, researchers who rely on vendor's specifications can be misinformed. The confusion regarding the binding specificities of MAL and MAH and its impact on the accurate use of M. amurensis seed lectins for glycoanalysis was previously noted in two publications (Nicholls et al. 2007; Varki and Varki 2007). However, no communication has focused specifically on this topic. Having experienced serious confusion in this area, we thought it would be useful to review the binding properties of MAL and MAH and illustrate their utility as glycoanalytical tools in a controlled lectin-blotting assay. Maackia amurensis seed lectin-binding specificities defined by direct studies References: 1, Imberty et al. (2000); 2, Johansson et al. (1999); 3, Kaku et al. (1993); 4, Knibbs et al. (1991); 5, Nicholls et al. (2007); 6, Wang and Cummings (1988); 7, Yamamoto et al. (2005); 8, CFG glycan array for MAL; 9, Kawaguchi et al. (1974b); 10, Brinkman-Van der Linden et al. (2002); 11, Konami et al. (1994); 12, Maenuma et al. (2008); 13, Maenuma et al. (2009); 14, CFG glycan array for MAH; 15, Bai et al. (2001). †Some researchers investigated binding specificity using glycans with Glc instead of GlcNAc on the reducing end. ‡MAL also recognizes the structure (Siaα2-8)nSiaα2-3Galβ1-4GlcNAc, but not polysialic acid (Siaα2-8)n per se. Maackia amurensis seed lectin-binding specificities defined by direct studies References: 1, Imberty et al. (2000); 2, Johansson et al. (1999); 3, Kaku et al. (1993); 4, Knibbs et al. (1991); 5, Nicholls et al. (2007); 6, Wang and Cummings (1988); 7, Yamamoto et al. (2005); 8, CFG glycan array for MAL; 9, Kawaguchi et al. (1974b); 10, Brinkman-Van der Linden et al. (2002); 11, Konami et al. (1994); 12, Maenuma et al. (2008); 13, Maenuma et al. (2009); 14, CFG glycan array for MAH; 15, Bai et al. (2001). †Some researchers investigated binding specificity using glycans with Glc instead of GlcNAc on the reducing end. ‡MAL also recognizes the structure (Siaα2-8)nSiaα2-3Galβ1-4GlcNAc, but not polysialic acid (Siaα2-8)n per se. Wide variety of M. amurensis seed lectin-binding specificities cited in glycoanalytical studies or by commercial vendors References: 1, Brownlee et al. (2007)†; 2, Dorscheid et al. (1999); 3, Meagher et al. (2005); 4, Yamada et al. (2006); 5, Vector labs catalog 2010†; 6, Bio-world catalog 2010; 7, Carpenter et al. (1996); 8, Chen et al. (2008); 9, Giannasca et al. (1997); 10, Legardinier et al. (2005); 11, Ohyama et al. (2004); 12, Dalmasso et al. (2000); 13, Grange et al. (2002); 14, Tatsuzuki et al. (2009); 15, Axxora catalog 2010†; 16, Pan et al. (2002); 17, Bio-world catalog 2010; 18, Nozaki et al. (2007); 19, Vercoutter-Edouart et al. (2008); 20, Hennet et al. (1998); 21, Yao et al. (2008); 22, Jarvis and Finn (1995); 23, Marchal et al. (2001); 24, Pilobello et al. (2005); 25, Roche DIG Glycan Differentiation Kit; 26, Sigma-Aldrich catalog 2010. †“Tolerates” Neu5Ac linked to carbon 3 of galactose. ‡MAA is an undefined mixture of MAL and MAH. Wide variety of M. amurensis seed lectin-binding specificities cited in glycoanalytical studies or by commercial vendors References: 1, Brownlee et al. (2007)†; 2, Dorscheid et al. (1999); 3, Meagher et al. (2005); 4, Yamada et al. (2006); 5, Vector labs catalog 2010†; 6, Bio-world catalog 2010; 7, Carpenter et al. (1996); 8, Chen et al. (2008); 9, Giannasca et al. (1997); 10, Legardinier et al. (2005); 11, Ohyama et al. (2004); 12, Dalmasso et al. (2000); 13, Grange et al. (2002); 14, Tatsuzuki et al. (2009); 15, Axxora catalog 2010†; 16, Pan et al. (2002); 17, Bio-world catalog 2010; 18, Nozaki et al. (2007); 19, Vercoutter-Edouart et al. (2008); 20, Hennet et al. (1998); 21, Yao et al. (2008); 22, Jarvis and Finn (1995); 23, Marchal et al. (2001); 24, Pilobello et al. (2005); 25, Roche DIG Glycan Differentiation Kit; 26, Sigma-Aldrich catalog 2010. †“Tolerates” Neu5Ac linked to carbon 3 of galactose. ‡MAA is an undefined mixture of MAL and MAH. The presence of he